The neuro-invasive potential of SARS-CoV-2; A threat of viral latency

2021 ◽  
Author(s):  
Fabiha Qayyum
Keyword(s):  
Viral Latency ◽  
Invasive Potential

Ultrastructural features of prognostic significance in human oral cancer

1992 ◽  
Vol 50 (1) ◽  
pp. 618-619
Author(s):  
Karvita B. Ahluwalia ◽  
Nidhi Sharma
Keyword(s):  
Oral Cancer ◽  
Squamous Cell ◽  
Common Knowledge ◽  
Prognostic Significance ◽  
Growth Control ◽  
Terminal Differentiation ◽  
Squamous Cell Carcinomas ◽  
Effective Therapy ◽  
Invasive Potential ◽  
Biological Behaviour

It is common knowledge that apparently similar tumors often show different responses to therapy. This experience has generated the idea that histologically similar tumors could have biologically distinct behaviour. The development of effective therapy therefore, has the explicit challenge of understanding biological behaviour of a tumor. The question is which parameters in a tumor could relate to its biological behaviour ? It is now recognised that the development of malignancy requires an alteration in the program of terminal differentiation in addition to aberrant growth control. In this study therefore, ultrastructural markers that relate to defective terminal differentiation and possibly invasive potential of cells have been identified in human oral leukoplakias, erythroleukoplakias and squamous cell carcinomas of the tongue.

scholarly journals All Shades of Shrimp: Preferences of Colour Morphs of a Freshwater Shrimp Neocaridina davidi (Decapoda, Atyidae) for Substrata of Different Colouration

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1071
Author(s):  
Zuzanna Plichta ◽  
Jarosław Kobak ◽  
Rafał Maciaszek ◽  
Tomasz Kakareko
Keyword(s):  
Invasive Species ◽  
Niche Breadth ◽  
Habitat Preferences ◽  
Choice Experiments ◽  
Freshwater Shrimp ◽  
Invasive Potential ◽  
Proper Management ◽  
Aquarium Hobby ◽  
Colour Morphs ◽  
Background Pattern

An ornamental freshwater shrimp, Neocaridina davidi, is popular as an aquarium hobby and, therefore, a potentially invasive species. There is a growing need for proper management of this species to determine not only their optimum breeding conditions, but also their ability to colonise novel environments. We tested habitat preferences of colour morphs (brown, red, white) of N. davidi for substratum colour (black, white, grey shades, red) and fine or coarse chess-board patterns to recognise their suitable captivity conditions and predict their distribution after potential release into nature. We conducted laboratory choice experiments (n = 8) with three individuals of the same morph exposed for two hours to a range of backgrounds. Shrimp preferred dark backgrounds over light ones irrespective of their own colouration and its match with the background colour. Moreover, the brown and red morphs, in contrast to the white morph, preferred the coarse background pattern over the finer pattern. This suggests that the presence of dark, uniform substrata (e.g., rocks, macrophytes) will favour N. davidi. Nevertheless, the polymorphism of the species has little effect on its total niche breadth, and thus its invasive potential.

scholarly journals Multiscale modeling of glioma pseudopalisades: contributions from the tumor microenvironment

2021 ◽  
Vol 82 (6) ◽  
Author(s):  
Pawan Kumar ◽  
Jing Li ◽  
Christina Surulescu
Keyword(s):  
Multiscale Modeling ◽  
Reaction Diffusion ◽  
Tumor Grade ◽  
Invasive Potential ◽  
Macroscopic System ◽  
Active Particles ◽  
Reaction Diffusion Model ◽  
Different Types ◽  
Parabolic Scaling ◽  
Parameter Ranges

AbstractGliomas are primary brain tumors with a high invasive potential and infiltrative spread. Among them, glioblastoma multiforme (GBM) exhibits microvascular hyperplasia and pronounced necrosis triggered by hypoxia. Histological samples showing garland-like hypercellular structures (so-called pseudopalisades) centered around the occlusion site of a capillary are typical for GBM and hint on poor prognosis of patient survival. We propose a multiscale modeling approach in the kinetic theory of active particles framework and deduce by an upscaling process a reaction-diffusion model with repellent pH-taxis. We prove existence of a unique global bounded classical solution for a version of the obtained macroscopic system and investigate the asymptotic behavior of the solution. Moreover, we study two different types of scaling and compare the behavior of the obtained macroscopic PDEs by way of simulations. These show that patterns (not necessarily of Turing type), including pseudopalisades, can be formed for some parameter ranges, in accordance with the tumor grade. This is true when the PDEs are obtained via parabolic scaling (undirected tissue), while no such patterns are observed for the PDEs arising by a hyperbolic limit (directed tissue). This suggests that brain tissue might be undirected - at least as far as glioma migration is concerned. We also investigate two different ways of including cell level descriptions of response to hypoxia and the way they are related .

scholarly journals Invasive lizard has fewer parasites than native congener

2021 ◽  
Author(s):  
Beatriz Tomé ◽  
D. James Harris ◽  
Ana Perera ◽  
Isabel Damas-Moreira
Keyword(s):  
18S Rrna ◽  
Blood Parasites ◽  
Average Intensity ◽  
Invasive Potential ◽  
Lizard Species ◽  
High Prevalence ◽  
Podarcis Siculus ◽  
Species Establishment ◽  
Low Levels ◽  
Italian Wall Lizard

AbstractInvasive species can carry parasites to introduced locations, which may be key to understand the success or failure of species establishment and the invasive potential of introduced species. We compared the prevalence and infection levels of haemogregarine blood parasites between two sympatric congeneric species in Lisbon, Portugal: the invasive Italian wall lizard (Podarcis siculus) and the native green Iberian wall lizard (Podarcis virescens). The two species had significant differences in their infection levels: while P. virescens had high prevalence of infection (69.0%), only one individual of P. siculus was infected (3.7%), and while P. virescens exhibited an average intensity of 1.36%, the infected P. siculus individual had an infection rate of only 0.04%. Genetic analyses of 18S rRNA identified two different haemogregarine haplotypes in P. virescens. Due to the low levels of infection, we were not able to amplify parasite DNA from the infected P. siculus individual, although it was morphologically similar to those found in P. virescens. Since other studies also reported low levels of parasites in P. siculus, we hypothesize that this general lack of parasites could be one of the factors contributing to its competitive advantage over native lizard species and introduction success.

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